Solvent extraction (SX)/electrolyte filter systems are used to remove organic molecules from an electrolyte solution. Such systems are used, for example, in the copper mining industry.
Air floatation columns have been used with SX/electrolyte filter systems. In such uses, dissolved air is first introduced into the solution so that it adheres to the organic molecules in the system, which molecules are thereby raised as the air floats to the top of a floatation column. After the air flotation process, the solution is passed on to the filter system for further removal of organic molecules remaining in the solution.
FIG. 1 illustrates a prior art coalesce operational process with an SX filter 10 and floatation column 12. The floatation column 12 operates in front of the filter 10 and introduces air bubbles at 14 into the electrolyte solution which is fed at 16 into the floatation column 12. The air bubbles are created by regulating plant air into the column 12. The introduced air bubbles adhere to some of the organic molecules which are, as a result, caused to float to the top of the system, allowing their removal from the floatation column at 18. Such columns typically have 45 to 60 percent organic material removal efficiency.
The electrolyte solution from which some of the organic molecules have been removed is then output at 20 from the floatation column 12 and passed on to the SX filter 10 for further organic material removal such as is known an illustrated in FIG. 1 (i.e., by passing the solution through coalescing media 24 at the bottom of the filter 10 by outputting the solution out the outlet 26 at the bottom).
It should be appreciated that if the floatation column 12 provides a 60 percent removal efficiency and the SX filter 10 provides a 90 percent efficiency, the combined floatation column 12 and SX filter 10 would have about a 96 percent removal efficiency. For example, if 100 PPM of organic molecules enters the feed 16, then the filtered solution exiting the SX filter 10 would have about 4 PPM organic molecules. However, at increased feed flow rates, the combined floatation column 12 and SX filter 10 is not effective at removing organic molecules. As a result, copper manufacturers who use this system have been able to produce middle and high end copper quality at design flow rates, but at high flow rates the copper quality would diminish rapidly, and shutdowns would occur.
Moreover, the equipment used in this dual separation process of the combined floatation column 12 and SX filter 10 is not only costly, but also costly to operate and maintain in order to allow for operation at design conditions on a yearly basis.
The present invention is directed toward overcoming one or more of the problems set forth above.